ID A0A0E3SGC5_9EURY Unreviewed; 258 AA.
AC A0A0E3SGC5;
DT 24-JUN-2015, integrated into UniProtKB/TrEMBL.
DT 24-JUN-2015, sequence version 1.
DT 24-JAN-2024, entry version 34.
DE RecName: Full=Probable S-methyl-5'-thioinosine phosphorylase {ECO:0000256|HAMAP-Rule:MF_01963};
DE EC=2.4.2.44 {ECO:0000256|HAMAP-Rule:MF_01963};
DE AltName: Full=5'-methylthioinosine phosphorylase {ECO:0000256|HAMAP-Rule:MF_01963};
DE Short=MTI phosphorylase {ECO:0000256|HAMAP-Rule:MF_01963};
DE Short=MTIP {ECO:0000256|HAMAP-Rule:MF_01963};
GN ORFNames=MSHOH_2909 {ECO:0000313|EMBL:AKB79392.1};
OS Methanosarcina horonobensis HB-1 = JCM 15518.
OC Archaea; Euryarchaeota; Stenosarchaea group; Methanomicrobia;
OC Methanosarcinales; Methanosarcinaceae; Methanosarcina.
OX NCBI_TaxID=1434110 {ECO:0000313|EMBL:AKB79392.1, ECO:0000313|Proteomes:UP000033101};
RN [1] {ECO:0000313|EMBL:AKB79392.1, ECO:0000313|Proteomes:UP000033101}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=HB-1 {ECO:0000313|EMBL:AKB79392.1,
RC ECO:0000313|Proteomes:UP000033101};
RA Henriksen J.R., Luke J., Reinhart S., Benedict M.N., Youngblut N.D.,
RA Metcalf M.E., Whitaker R.J., Metcalf W.W.;
RT "Methanogenic archaea and the global carbon cycle.";
RL Submitted (JUL-2014) to the EMBL/GenBank/DDBJ databases.
CC -!- FUNCTION: Catalyzes the reversible phosphorylation of S-methyl-5'-
CC thioinosine (MTI) to hypoxanthine and 5-methylthioribose-1-phosphate.
CC Involved in the breakdown of S-methyl-5'-thioadenosine (MTA), a major
CC by-product of polyamine biosynthesis. Catabolism of (MTA) occurs via
CC deamination to MTI and phosphorolysis to hypoxanthine.
CC {ECO:0000256|HAMAP-Rule:MF_01963}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=phosphate + S-methyl-5'-thioinosine = hypoxanthine + S-methyl-
CC 5-thio-alpha-D-ribose 1-phosphate; Xref=Rhea:RHEA:30643,
CC ChEBI:CHEBI:17368, ChEBI:CHEBI:43474, ChEBI:CHEBI:48595,
CC ChEBI:CHEBI:58533; EC=2.4.2.44; Evidence={ECO:0000256|HAMAP-
CC Rule:MF_01963};
CC -!- PATHWAY: Purine metabolism; purine nucleoside salvage.
CC {ECO:0000256|HAMAP-Rule:MF_01963}.
CC -!- SUBUNIT: Homotrimer. {ECO:0000256|HAMAP-Rule:MF_01963}.
CC -!- MISCELLANEOUS: Although this enzyme belongs to the family of MTA
CC phosphorylases based on sequence homology, it has been shown that
CC conserved amino acid substitutions in the substrate binding pocket
CC convert the substrate specificity of this enzyme from 6-aminopurines to
CC 6-oxopurines. {ECO:0000256|HAMAP-Rule:MF_01963}.
CC -!- SIMILARITY: Belongs to the PNP/MTAP phosphorylase family. MTAP
CC subfamily. {ECO:0000256|HAMAP-Rule:MF_01963}.
CC -!- CAUTION: Lacks conserved residue(s) required for the propagation of
CC feature annotation. {ECO:0000256|HAMAP-Rule:MF_01963}.
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DR EMBL; CP009516; AKB79392.1; -; Genomic_DNA.
DR RefSeq; WP_048143552.1; NZ_CP009516.1.
DR AlphaFoldDB; A0A0E3SGC5; -.
DR STRING; 1434110.MSHOH_2909; -.
DR GeneID; 24832233; -.
DR KEGG; mhor:MSHOH_2909; -.
DR PATRIC; fig|1434110.4.peg.3751; -.
DR HOGENOM; CLU_054456_0_2_2; -.
DR OrthoDB; 7681at2157; -.
DR UniPathway; UPA00606; -.
DR Proteomes; UP000033101; Chromosome.
DR GO; GO:0017061; F:S-methyl-5-thioadenosine phosphorylase activity; IEA:InterPro.
DR GO; GO:0006166; P:purine ribonucleoside salvage; IEA:UniProtKB-UniRule.
DR CDD; cd09010; MTAP_SsMTAPII_like_MTIP; 1.
DR Gene3D; 3.40.50.1580; Nucleoside phosphorylase domain; 1.
DR HAMAP; MF_01963; MTAP; 1.
DR InterPro; IPR010044; MTAP.
DR InterPro; IPR000845; Nucleoside_phosphorylase_d.
DR InterPro; IPR035994; Nucleoside_phosphorylase_sf.
DR NCBIfam; TIGR01694; MTAP; 1.
DR PANTHER; PTHR42679; S-METHYL-5'-THIOADENOSINE PHOSPHORYLASE; 1.
DR PANTHER; PTHR42679:SF2; S-METHYL-5'-THIOADENOSINE PHOSPHORYLASE; 1.
DR Pfam; PF01048; PNP_UDP_1; 1.
DR SUPFAM; SSF53167; Purine and uridine phosphorylases; 1.
PE 3: Inferred from homology;
KW Glycosyltransferase {ECO:0000256|HAMAP-Rule:MF_01963,
KW ECO:0000313|EMBL:AKB79392.1};
KW Purine salvage {ECO:0000256|HAMAP-Rule:MF_01963};
KW Transferase {ECO:0000256|HAMAP-Rule:MF_01963, ECO:0000313|EMBL:AKB79392.1}.
FT DOMAIN 10..238
FT /note="Nucleoside phosphorylase"
FT /evidence="ECO:0000259|Pfam:PF01048"
FT BINDING 53..54
FT /ligand="phosphate"
FT /ligand_id="ChEBI:CHEBI:43474"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01963"
FT BINDING 180
FT /ligand="substrate"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01963"
FT BINDING 181
FT /ligand="phosphate"
FT /ligand_id="ChEBI:CHEBI:43474"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01963"
FT BINDING 204..206
FT /ligand="substrate"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01963"
FT SITE 163
FT /note="Important for substrate specificity"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01963"
FT SITE 216
FT /note="Important for substrate specificity"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_01963"
SQ SEQUENCE 258 AA; 28136 MW; 2434F6B9557910BB CRC64;
MDTVDEVAEI AVLGGVGFSS YRDCESHPVK TPYGGVTAYI TSIKGKRVAI IPRHAEEIHI
PPHRVNYRAN VWAAHSLGVK RVISTNSVGS MRGHPVGSFV VLDDFIDFTR SRSSTFYDEK
TVHVDVTEPY CPEIKAALKY ALGKQGLSYT EGIYACTEGP RFETRAEIRM MSQFADVVGM
TGVPEVVLAK ELSLCYASLA IVTNQACGMA TQKLTADEVT EVVGKAQDSI FEILSDAIGK
IPETRNCMCR FAKEGACL
//
